Last week’s announcement that another two dozen Catholic schools in New York will soon close left many area families reeling. For the poorest and most disadvantaged New Yorkers, Catholic schools provide the only reasonably priced alternative to the failing public-school system. What’s being done to keep that option alive?

As Sol Stern noted in City Journal last year, “In New York’s inner-city Catholic high schools, over 80 percent of disadvantaged minority students graduate on time, almost doubling the public school rate.” And they do it “despite spending just $10,000 per high schooler” — less than half the public schools’ rate.

Thanks to the church’s subsidies and private scholarship funds, many poor parents pay only a few hundred dollars a year for this superior education.

But the church can only afford so much, and schools’ costs keep rising.

In 1920, Catholic schools nationwide drew 92 percent of staff from religious orders; now it’s less than 4 percent. Not only was the labor cheap, but school principals had the complete moral and financial support of the parish.

There are other new expenses. As Robert Flanigan, a member of the Executive Committee of the Archdiocese’s Patrons, notes, today’s students have a “broader range of needs. Principals need to understand legal issues, personnel issues, technology.”

One solution, says Flanigan, is “great leadership.” In 2008, he helped found the Curran Principals Academy, a program that partners with the Archdiocese and the Diocese of Brooklyn to identify and train leaders in Catholic schools. The program’s third cohort of 16 students is now in the process of getting their master’s in educational leadership, mostly at St. John’s University.

Margaret Carter, who runs the program, explains that the “focus is on board development, marketing, enrollment management… things that principals might not have looked at in past.”

Cara Joyce, daughter of a lifelong Catholic school educator, knows the old and the new realities. After graduating from Holy Cross College five years ago, she volunteered (through Americorps) at the Connelly Middle School on the Lower East Side. Its students come entirely from low-income minority families.

She eventually moved up to assistant principal; now she’s getting an advanced degree from the Mary Ann Remick Leadership Program at Notre Dame, gaining the skills to manage a modern urban Catholic school.

One of her first classes last summer was in finance. “We were all asked to bring our schools’ budgets. And we spent four hours a day for three weeks going through them.” Budgeting is about values as well as money: Balancing the need for renovations with keeping salaries for teachers competitive or adding enrichment activities for children. She’s learned “the importance of making financial decisions that are good for that year and for the long term.”

Sister Barbara Kane, a graduate of the Remick program, is now the principal at Dominican Academy in Manhattan. At her order’s request, she moved here from Ohio in 2008, where she had a background working both in Catholic education and in business. The Remick program helped her apply her business expertise to a school environment. “We have a board, we have investments, I have a working knowledge of how those things work.”

Ultimately, she tells me, “In order for Catholic schools to survive, you need to balance a budget and make hard decisions about expenses and tuition that will ensure we can stay viable for a long time.” Here’s hoping.

But all this innovation may not be enough. Flanigan also sees a need “to level the economic playing field. The fact that parents in low-income neighborhoods have to pay is a great challenge.” The obvious answer is for New York to adopt some kind of voucher or tuition-tax-credit program, as several other states have.

Vested interests and ideologies have long blocked any such reform in these parts — but the state actually has a clear interest in keeping the Catholic schools healthy. If they’re all forced to close, Timothy Cardinal Dolan estimates, New Yorkers would be on the hook for another $3 billion a year to educate these children.

Catholic schools have a long history of high performance and an infrastructure of expert, caring teachers and principals. But once they go away, we can’t get them back.